In recent years, the market of flash storage products tends to expand, and there is a demand for larger capacity and higher performance of flash storage. In order to make the flash storage have larger capacity, it is necessary to mount a plurality of memory chips, and to increase signal lines for chip selection which are outputted by a memory controller as the number of the memory chips increases.
PTL 1 describes that “A memory system, including a NAND memory mounted with a plurality of Chips, and a NAND controller 112 for controlling the NAND memory, is provided with a bus switch for switching connections of a signal line between the NAND controller 112 and the plurality of Chips mounted on the NAND memory, so that load capacities of the signal lines during an access to a NAND memory 10 are reduced and signal delay is prevented.”.